Photo: JAXA
Earth may avoid destruction when the Sun reaches the end of its life, according to new research that challenges long-standing predictions. Using advanced computer models, scientists found that our planet could escape being swallowed as the Sun expands into a red giant, Live Science reports.
The Sun, a yellow dwarf star, is expected to live for around 10 billion years. In roughly five billion years, it will exhaust the hydrogen in its core and begin expanding into a red giant before eventually shedding its outer layers and ending its life as a white dwarf.
Researchers revisited Earth’s fate by studying L2 Puppis, a dying star about 200 light-years away that resembles what the Sun may become. Their findings suggest Earth’s future depends on a delicate balance between two competing forces.
As the Sun expands, its stronger tidal forces would pull Earth inward. At the same time, the star will lose a significant amount of its mass, weakening its gravitational pull and allowing Earth’s orbit to drift farther away.
“Earth’s fate depends on the balance between these two effects. If tidal forces dominate, the planet will be engulfed. If mass loss dominates, Earth will move to a wider orbit,” said lead author Mats Esselderts, a PhD researcher at the Institute of Astronomy at KU Leuven in Belgium.
Earlier studies reached different conclusions because they relied on varying assumptions about solar mass loss, tidal interactions and planetary dynamics. To refine the predictions, the team combined observations of L2 Puppis with updated models of stellar evolution and the future dynamics of the inner Solar System.
The simulations indicate that Earth could survive by moving beyond the Sun’s expanding outer layers. However, the researchers caution that the biggest uncertainty is still how much mass the Sun will lose during its final stages.
“The main uncertainty is no longer the tidal calculations, but how much mass the future Sun will lose. Observations of Sun-like giant stars currently suggest Earth could survive, but we need better data before we can be certain,” Esselderts said.
Even if Earth escapes destruction, the study suggests Mercury and Venus will almost certainly be consumed by the expanding Sun.
The findings offer a new perspective on the long-term future of the Solar System and highlight how observations of dying stars can improve scientists’ understanding of stellar evolution.
